Nombre total de pages

ISBN

URL de l'ouvrage

URI

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Métadonnées

Auteur

Hassin, Refael

Monnot, Jérôme

Segev, Danny

Type

Communication / Conférence

Nombre de pages du document

480-491

Résumé en anglais

Let G = (V,E) be a connected multigraph, whose edges are associated with labels specified by an integer-valued function ${\mathcal{L}} : E \rightarrow \mathbb{N}$ . In addition, each label $\ell \in \mathbb{N}$ to which at least one edge is mapped has a non-negative cost c( ℓ). The minimum label spanning tree problem (MinLST) asks to find a spanning tree in G that minimizes the overall cost of the labels used by its edges. Equivalently, we aim at finding a minimum cost subset of labels $I \subseteq \mathbb{N}$ such that the edge set $\{ e \in E : {\mathcal {L}}( e ) \in I \}$ forms a connected subgraph spanning all vertices. Similarly, in the minimum label s-t path problem (MinLP) the goal is to identify an s-t path minimizing the combined cost of its labels, where s and t are provided as part of the input.
The main contributions of this paper are improved approximation algorithms and hardness results for MinLST and MinLP. As a secondary objective, we make a concentrated effort to relate the algorithmic methods utilized in approximating these problems to a number of well-known techniques, originally studied in the context of integer covering.